Play toys for use by pets, particularly dogs, have been commercially available for years. Those particularly designed for dogs are generally shaped like a dog bone. However, dog toys having ring-like and ball shapes are also sometimes seen in the marketplace. Most dog toys, are also made from a rubber-like material so that the toy will bounce when played with by the dog. Researchers studying dog behavior discovered years ago that dogs prefer toys having bouncing characteristics.
U.S. Pat. No. Des. 256,958 which issued on Sept. 16, 1980 to Markham, a coinventor of the present invention, discloses a pet toy, preferably made from rubber, which provides pets, primarily dogs, with masticatory exercise when they chew the toy. The toy has two circumferentially extending shallow grooves which facilitate a dog's chewing of the toy.
U.S. Pat. Nos. Des. 234,789 and Des. 234,790 to Rosenberg disclose sounding toys having spiraling members which define chambers for housing objects secured therein. The objects rattle when a pet plays with the toy. The toy is not disclosed as having an utility as a chewing toy for pets, nor does the design lend itself to such utility. While the toys are possibly resilient in a direction parallel to the toy's longitudinal axis, the spiraling members would not appear to provide the toy with much give or elasticity in a direction perpendicular to the longitudinal axis. Accordingly, it is unlikely that a dog would chew these toys.
U.S. Pat. No. 2,194,736 to De Bruler discloses a tether pet toy which includes a dog bone shaped member which is attached to an elastic string-like member. The string-like member is attached to the dog bone member by wrapping and tying it about two lips provided on the dog bone. The lips prevent the string-like member from slipping off the dog bone.
U.S. Pat. No. 3,198,173 to Fisher discloses a pet toy made from a strip of rawhide wound and rolled into a loosely coiled configuration.
U.S. Pat. No. 2,185,547 to Fowler discloses a pet toy having a core which is covered by two pieces of rawhide sewn together.
U.S. Pat. Nos. 4,513,014 and 4,557,219 to Edwards disclose a dog bone shaped tough molded elastomeric chewable polyurethane toy for an animal. The toy has a longitudinal groove extending along a substantial portion of its midsection. The groove facilitates flexing of the dog bone at opposite sides of the groove to provide a satisfying crunching effect to the chewer.
The aforementioned patents demonstrate that very few pet toys have been specifically designed with features that are directed to improving a dog's dental health. Some of the more resilient or rubber-like toys described above inherently provide some massaging of a dog's gums as the dog chews the toy, but few are specifically designed for such purpose. Moreover, none of the toys discussed above were developed for the purpose of scraping or scaling plaque and other debris from a dog's teeth.